From owner-svn-src-head@freebsd.org Fri Jul 21 18:28:28 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4F55FDAE50C; Fri, 21 Jul 2017 18:28:28 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 1D1477EF9F; Fri, 21 Jul 2017 18:28:28 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v6LISRPA058986; Fri, 21 Jul 2017 18:28:27 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v6LISRaT058985; Fri, 21 Jul 2017 18:28:27 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201707211828.v6LISRaT058985@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Fri, 21 Jul 2017 18:28:27 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r321347 - head/sys/ufs/ffs X-SVN-Group: head X-SVN-Commit-Author: kib X-SVN-Commit-Paths: head/sys/ufs/ffs X-SVN-Commit-Revision: 321347 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Jul 2017 18:28:28 -0000 Author: kib Date: Fri Jul 21 18:28:27 2017 New Revision: 321347 URL: https://svnweb.freebsd.org/changeset/base/321347 Log: Account for lock recursion when transfering snaplock to the vnode lock in ffs_snapremove(). Apparently ffs_snapremove() may be called with the snap lock recursed, at least one trace demonstrated this when snapshot vnode was unlinked while synced. It was inactivated from the syncer thread. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Modified: head/sys/ufs/ffs/ffs_snapshot.c Modified: head/sys/ufs/ffs/ffs_snapshot.c ============================================================================== --- head/sys/ufs/ffs/ffs_snapshot.c Fri Jul 21 18:14:06 2017 (r321346) +++ head/sys/ufs/ffs/ffs_snapshot.c Fri Jul 21 18:28:27 2017 (r321347) @@ -1598,7 +1598,7 @@ ffs_snapremove(vp) struct buf *ibp; struct fs *fs; ufs2_daddr_t numblks, blkno, dblk; - int error, loc, last; + int error, i, last, loc; struct snapdata *sn; ip = VTOI(vp); @@ -1618,10 +1618,14 @@ ffs_snapremove(vp) ip->i_nextsnap.tqe_prev = 0; VI_UNLOCK(devvp); lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); + for (i = 0; i < sn->sn_lock.lk_recurse; i++) + lockmgr(&vp->v_lock, LK_EXCLUSIVE, NULL); KASSERT(vp->v_vnlock == &sn->sn_lock, ("ffs_snapremove: lost lock mutation")); vp->v_vnlock = &vp->v_lock; VI_LOCK(devvp); + while (sn->sn_lock.lk_recurse > 0) + lockmgr(&sn->sn_lock, LK_RELEASE, NULL); lockmgr(&sn->sn_lock, LK_RELEASE, NULL); try_free_snapdata(devvp); } else